The present invention relates to azo dyes and to their use for dyeing or printing nitrogen-containing or hydroxyl group-containing natural or synthetic materials, in particular synthetic polyamide fibre materials.
It is the object of this invention to provide yellow- or orange-dyeing dyes which are suitable for dyeing or printing nitrogen-containing or hydroxyl group-containing natural or synthetic fibre materials, in particular natural or, more preferably, synthetic polyamide fibre materials, and which have good allround fastness properties and, in particular, good lightfastness, good solubility and good printing paste stability as well as good compatibility with red and blue dyes in trichromatic dyeing processes.
It has now been found that the following dyes substantially meet these requirements.
Accordingly, this invention relates to dyes of formula 
wherein
R1 is hydrogen, halogen, C1-C8alkyl, xe2x80x94NHxe2x80x94COxe2x80x94C1-C4alkyl or phenyl,
R2 is hydrogen, halogen, C1-C8alkyl, C1-C8alkoxy, xe2x80x94NHxe2x80x94COxe2x80x94C1-C4alkyl or phenyl,
R3 is hydrogen, C1-C8alkyl or phenyl,
R4 is hydrogen, halogen or C1-C8alkyl, and
X is xe2x80x94COxe2x80x94, xe2x80x94COOxe2x80x94 or xe2x80x94SO2xe2x80x94, and
n is the number 1 or 2.
R1 defined as C1-C8alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl and octyl.
R2 defined as C1-C8alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl and octyl.
R3 defined as C1-C8alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl and octyl.
R4 defined as C1-C8alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl and octyl.
R2 defined as C1-C8alkoxy is, for example, methoxy, ethoxy, propoxy and butoxy.
xe2x80x94NHxe2x80x94COxe2x80x94C1-C4alkyl is preferably xe2x80x94NHxe2x80x94COxe2x80x94CH3 and xe2x80x94NHxe2x80x94COxe2x80x94C2H5.
X is preferably xe2x80x94COxe2x80x94.
R1 is preferably tert-butyl and methyl.
R2 is preferably xe2x80x94C(CH3)2CH2CH3, xe2x80x94C(CH3)2CH2C(CH3)3 and tert-butyl.
R3 is preferably ethyl and methyl.
R4 is preferably methyl and hydrogen.
R1 is also preferably halogen, in particular chloro.
R2 is also preferably methoxy and halogen, in particular chloro.
R1 is particularly preferably methyl.
R2 is particularly preferably tert-butyl.
R3 is particularly preferably methyl.
R4 is particularly preferably hydrogen.
R1 is preferably bound in ortho-position to hydroxy.
R2 is preferably bound in para-position to hydroxy.
The azo bridge is preferably bound in ortho-position to the hydroxy.
xe2x80x94NHxe2x80x94Xxe2x80x94R3 is preferably bound in para-position to the azo bridge.
n is preferably the number 1.
Preferred dyes of formula (1) are those of formula 
wherein
R1, R2, R3, R4 and X have the meanings and preferred meanings given above for formula (1).
Particularly preferred dyes of formula (1) are those of formula 
wherein
R5 is hydrogen, methyl, tert-butyl or chloro,
R6 is methyl, tert-butyl, xe2x80x94C(CH3)2CH2CH3, xe2x80x94C(CH3)2CH2C(CH3)3, methoxy, chloro or phenyl,
R7 is methyl, and
X is xe2x80x94COxe2x80x94.
Very particularly preferred dyes of formula (1) are those of formulae 
Of the dyes listed above, the dye of formula (111) is particularly important.
The dyes of formulae (1), (2) and (3) can be used as free acid or, preferably, in the form of salts, for example in the form of the Lixe2x80x94, Naxe2x80x94, Kxe2x80x94, NH4xe2x80x94, triethanolamine or triisopropanolamine salts, or as salts containing a cation which is obtained by reacting triethanolamine with ethylene oxide and/or propylene oxide.
The dyes of formulae (1) and (2) can be obtained, for example, by diazotising the compound of formula 
or of formula 
wherein
R3, R4 and X have the meanings given for formula (1) in the acid pH range and then reacting the diazonium compound so obtained with a compound of formula 
wherein
R1 and R2 have the meanings given for formula (1),
and with an aqueous sodium hydroxide solution at a pH in the range from 8 to 12, advantageously from 9.5 to 10.5.
The compounds of formulae (50) to (52) are known or can be prepared by methods generally known per se.
Another object of this invention are concentrated aqueous dye solutions, which comprise 5 to 50% by weight, preferably 10 to 50% by weight and, more preferably, 20 to 50% by weight, based on the entire weight of the solution, of a dye of formula (1). The dyes can be present in these concentrated aqueous solutions either in the form of free acids or in the form of the salts described above.
The novel concentrated aqueous solutions can contain further additives, for example urea, caprolactam or polyethylene glycol. The novel concentrated aqueous solutions may also contain substances inhibiting the growth of fungi and/or bacteria. The novel dye solutions furthermore have good resistance to hard water and can be diluted with water in any ratio, for example when preparing the dye liquor, without the dissolved dyes precipitating.
The novel dyes of formula (1) can be used in the customary dyeing and printing processes. In addition to water and the dyes, the dye liquors or printing pastes can also contain further additives, for example wetting agents, antifoams, leveling agents or agents influencing the properties of the textile material, for example softeners, additives for flame retarding finishing or dirt, water and oil repellents, as well as water softeners and natural or synthetic thickeners, such as alginates and cellulose ether.
The novel dyes of formula (1) are also suitable for dyeing from short liquors, for example in the continuous dyeing process or in the discontinuous and continuous foam dyeing processes.
The novel dyes of formula (1) are particularly distinguished by good take-up, good solubility, good stability of the printing paste as well as good compatibility. Furthermore, the novel dye solutions have good storage stability, their concentrated solutions, for example, being storage-stable for several months at temperatures from xe2x88x925 to +40xc2x0 C.
Level dyeings are obtained which have good allround fastness properties, in particular good fastness to rubbing, wetting, wet rubbing and light.
The novel dyes of formula (1) are particularly suitable for dyeing or printing hydroxyl group-containing or nitrogen-containing fibre materials. They are particularly suitable for dyeing or printing synthetic polyamide materials, for example polyamide 6 or polyamide 6,6, or silk, and they are also suitable for dyeing or printing blended fabrics or yarns of wool and synthetic polyamide. The cited material, in particular textile material, can be in any form of presentation, for example in the form of fibres, yarn, wovens or knitgoods and, in particular, in the form of carpets.